1. Field of the Invention
The invention relates to novel organopolysiloxanes with betaine groups and to processes for the synthesis of these compounds. It also relates to the use of these compounds in cosmetic preparations.
2. Description of the Prior Art
The use of organopolysiloxanes for the preparation of hair care products is well known. However, in "Chemie und Technologie der Silicone" (Chemistry and Technology of the Silicones) by Water Noll, Chemie Publishing House, 2nd edition, 1968, page 536, it is stated that normal polydimethylsiloxanols are unable to maintain the hairdo independently of the effects of moisture. Rather, the silicone would have to be fixed on the hair with the help of functional groups.
German Auslegeschrift No. 14 93 384 discloses organosiloxane compounds or mixtures of compounds of the formula: ##STR4## in which R represents hydrogen or CH.sub.3, X represents halogen, x=1 to 10, and y=0 to 8.5, and the ratio of y:x is not greater than 8.5:1.
These organosiloxanes with quaternary ammonium groups can be synthesized by reacting an epoxysiloxane compound having the formula ##STR5## in a known manner with dimethylamine, and converting the dimethylamino organosiloxane compound obtained which has the formula ##STR6## in a known manner with a hydrogen halide or with a methyl halide into the quaternary ammonium compound of the aforementioned formula.
According to U.S. Pat. No. 4,185,087, the aforementioned organopolysiloxanes with quaternary ammonium groups can be used for hair care products. As disclosed therein, simple aqueous shampoos may release soil from hair and remove an excess of grease. With most shampoos, however, degreasing of the hair would be carried out so thoroughly that damage to the hair could be observed. After washing, the hair becomes electrostatically charged and therefore difficult to comb. While the addition of lanolin derivatives, glycol, fatty esters or proteins improves the ability to handle the hair after washing, it does interfere with foaming. The hair would become somewhat sticky and feel unnatural. According to U.S. Pat. No. 4,185,087, the specific organpolysiloxanes with the quaternary ammonium groups should eliminate these disadvantages and improve the combability of the washed hair, give better hold to the hair set, and improve the gloss.
Similar teachings are contained in European Pat. Nos. 0 017 121 and 0 017 122 which describe organopolysiloxanes with quaternary ammonium groups for use in shampoos and hair conditioners to improve the combing properties of the hair. The compounds correspond to the general formula: ##STR7## in which R.sub.1 and R.sub.2 represent an alkyl radical with 1 to 4 carbon atoms or an aryl radical, p represents the numbers 0 to 50, and R the radicals: ##STR8## in which R.sub.3 represents an alkyl or hydroxyalkyl radical with 1 to 3 carbon atoms, R.sub.4 represents a radical identical with R.sub.3, aryl--CH.sub.2 --, or the allyl radical, R.sub.5 represents hydrogen or the methyl radical, X.sup..crclbar. represents the anions Cl.sup..crclbar., Br.sup..crclbar., I.sup..crclbar., CH.sub.3 SO.sub.4.sup..crclbar. or C.sub.2 H.sub.5 SO.sub.4.sup..crclbar. and m the numbers 2 to 10 and n the numbers 2 to 4.
Finally, published European Patent Application No. 0095 238 discloses a composition which essentially comprises the following components:
(A) a siloxane of the general formula EQU R.sub.a X.sub.3-a Si(OSiX.sub.2).sub.n (OSiX.sub.b R.sub.2-b).sub.m OSiX.sub.3-a R.sub.a
in which R is only described functionally as a group which brings about adhesion to the hair, for example, an amino, carboxyl or quaternary ammonium group, X is a hydrogen radical or a phenyl, hydroxyl or saturated hydrocarbon group with 1 to 8 carbon atoms, a has a value of 0 to 3, b has a value of 0 to 1 and n+m has a value of 1 to 1999, n having a value from 0 to 2000 and m a value of 1 to 2000;
(B) a surfactant;
(C) an additive for improving the freeze/thaw stability, and
(D) water.
It therefore follows from the state of the art that organopolysiloxanes with quaternary ammonium groups have a strong substantivity on hair and endow it with good combability and gloss. However, their poor compatibility with anionic components, especially with anionic surfactants, is a disadvantage in hair care preparations. Moreover, they may also lead to irritation of the skin, especially of the mucous membrane, and to irritation of the eye which is extremely undesirable, especially in shampoos.